The invention relates to an arrangement of floating platforms, in particular for plants for the production of solar energy.
The production of so-called alternative energy, in particular of solar energy, has been continuously rising. Due to the relatively large space required for solar power plants, the aim is to transfer them to water surfaces, in particular of the oceans (“offshore solar power plants”). Recently, various floating platforms have been developed for this purpose to carry the respective plants. Because of the requirements of a simple and lightweight design, at the same time with high load capacity, the newest platforms developed are carried by air cushions. To increase the efficiency of solar power plants carried thereon, it is important to be able to orient the platforms toward the sun, i.e. track the sun.
International patent application publication WO 2009/001225 A2, as well as Austrian Patent Application AT 509.639 A1 to Heliovis, published after the priority date of the present application, both describe preferably circular floating platforms having flexible covers each defining a hollow space that can be set under over-pressure to create the required buoyancy. The platforms are rotatable as a whole to orient their position according to the sun. Preferred embodiments in WO 2009/001225 A2 cause the rotation by wheels in a ring surrounding the platform, for which purpose the platform has to float in a circular pool. According to AT 509.639 A1, engines having water propellers are used for rotating the platform.
However, neither of these references describes how an arrangement of such platforms, i.e. of several platforms, can be used for exploiting solar energy and be oriented toward the sun, even though the large space required for a solar energy plant very often makes it necessary to divide the respective equipment on more than one floating platform, in particular to equip several platforms with solar collectors, and to operate them floating on the sea or other waters.
Systems comprising several external platforms arranged around a central platform are described in the Patent Application Publications US 2008/257398 A1 and DE 10 2006 019 753 A1. In these platform systems, external platforms are rotatable around a stationary base, wherein in both cases the use of central, engine-driven gear rings engaging into the respective counterparts on the external platforms as drive units is disclosed. That is, rotation of the external platforms is achieved by transmission of a torque from the central to the external platforms, wherein the central platform can either also be (partly) set in rotational motion (DE 10 2006 019 753 A1) or not (US 2008/257398 A1). However, in both cases a non-rotatable anchorage of the central platform on the ground (e.g. sea bottom) is required, without which no torque could be transmitted outwards.
Despite its misleading title “Floating Solar Platform,” US 2008/257398 A1 describes a system that does not comprise any floating platforms at all, but three external platforms arranged around a central platform made of concrete, which external platforms serve as water basins, i.e., they contain a (shallow) water body on which lightweight soar collectors float. Thus, this system is neither designed for offshore use nor would it be suitable therefor.
In the system of DE 10 2006 019 753 A1, an upper part of a central platform called “rotating body” is set in rotation via a gear ring, which causes external platforms firmly connected thereto to rotate therewith. Furthermore, the external platforms carrying sun collectors each comprise a floating body that can be alternately filled with water or air, so that the platforms can be tilted around a horizontal axis in order to orient them toward the position of the sun.
However, none of the systems according to the state of the art describes a platform arrangement in which the external platforms carrying solar collectors can be moved independently of the central platform.